FromFiniteFieldIndex[ind,ff]
gives the element of the finite field ff with index ind.
FromFiniteFieldIndex
FromFiniteFieldIndex[ind,ff]
gives the element of the finite field ff with index ind.
Details
- FromFiniteFieldIndex has the Listable attribute.
- FromFiniteFieldIndex[ind,ff] is equivalent to ff[ind].
- If ff is FiniteField[p,f,"Polynomial"], then FromFiniteFieldIndex[ind,ff] is equal to IntegerDigits[ind,p,d].{αd-1,…,α0}, where α is the field generator of ff and d is the degree of f.
- If ff is FiniteField[p,f,"Exponential"] and ind≠0, then FromFiniteFieldIndex[ind,ff] is equal to αind-1, where α is the field generator of ff. FromFiniteFieldIndex[0,ff] gives the field zero of ff.
Examples
open all close allBasic Examples (1)
Scope (3)
Create a finite field element with a given index:
FromFiniteFieldIndex[1234, FiniteField[11, 3]]Use a finite field in the exponential representation:
FromFiniteFieldIndex[123, FiniteField[3, 5, "Exponential"]]Create a vector and a matrix of finite field elements with given indices:
FromFiniteFieldIndex[{111, 222, 333}, FiniteField[7, 3]]FromFiniteFieldIndex[{{123, 234, 345}, {456, 567, 678}}, FiniteField[97, 5]]//MatrixFormApplications (1)
Properties & Relations (3)
For a single index, FromFiniteFieldIndex[ind,ff] is equivalent to ff[ind]:
ff = FiniteField[11, 3];
FromFiniteFieldIndex[1234, ff] === ff[1234]For a list of integers, ff[list] gives a single element with polynomial coefficients specified by list:
ff[{123, 234, 345}]123 + 234ff[{0, 1}] + 345 ff[{0, 1}] ^ 2FromFiniteFieldIndex[list,ff] gives a list of elements with indices specified by list:
FromFiniteFieldIndex[{123, 234, 345}, ff]Use FiniteFieldIndex to get indices of field elements:
FromFiniteFieldIndex[{123, 234, 345}, FiniteField[19, 2]]FiniteFieldIndex[%]ToFiniteField converts integers to elements of the prime subfield:
ToFiniteField[{123, 456, 789}, FiniteField[5, 7]]FromFiniteFieldIndex gives finite field elements with specified indices:
FromFiniteFieldIndex[{123, 456, 789}, FiniteField[5, 7]]Related Guides
History
Text
Wolfram Research (2024), FromFiniteFieldIndex, Wolfram Language function, https://reference.wolfram.com/language/ref/FromFiniteFieldIndex.html.
CMS
Wolfram Language. 2024. "FromFiniteFieldIndex." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/FromFiniteFieldIndex.html.
APA
Wolfram Language. (2024). FromFiniteFieldIndex. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/FromFiniteFieldIndex.html
BibTeX
@misc{reference.wolfram_2026_fromfinitefieldindex, author="Wolfram Research", title="{FromFiniteFieldIndex}", year="2024", howpublished="\url{https://reference.wolfram.com/language/ref/FromFiniteFieldIndex.html}", note=[Accessed: 13-June-2026]}
BibLaTeX
@online{reference.wolfram_2026_fromfinitefieldindex, organization={Wolfram Research}, title={FromFiniteFieldIndex}, year={2024}, url={https://reference.wolfram.com/language/ref/FromFiniteFieldIndex.html}, note=[Accessed: 13-June-2026]}